Comment on “On stability and application of extremum seeking control without steady-state oscillation” [Automatica 68 (2016) 18–26]

Automatica ◽  
2019 ◽  
Vol 103 ◽  
pp. 580-581 ◽  
Author(s):  
Khalid Tourkey Atta ◽  
Martin Guay
Keyword(s):  
Steady State ◽  
Extremum Seeking ◽  
Extremum Seeking Control ◽  
Steady State Oscillation

scholarly journals ON THE EXTREMUM-SEEKING CONTROL DESIGN AND APPLICATION FOR ANAEROBIC DIGESTION PROCESSES

2019 ◽  
pp. 23-28
Author(s):  
Maobo Hu ◽  
Haoping Wang ◽  
Yang Tian ◽  
Nicolai Christov ◽  
Ivan Simeonov
Keyword(s):  
Steady State ◽  
Anaerobic Digestion ◽  
Extremum Seeking ◽  
System Model ◽  
Extend Kalman Filter ◽  
Order Model ◽  
Extremum Seeking Control ◽  
Digestion Process ◽  
Steady State Oscillation ◽  
Fifth Order

The paper deals with the optimization of nonlinear systems by using Extremum Seeking Control (ESC) without any prior knowledge of the system model. An Extend Kalman Filter based Extremum Seeking Control (EKF based ESC) is proposed, which can make the amplitude of perturbation signal variable and ensure convergence to zero, i.e. without steady-state oscillation. The proposed ESC algorithm makes also possible to obtain more accurate gradient estimate and more rapid ESC convergence. The proposed EKF based ESC algorithm is applied to a fifth-order model of anaerobic digestion process and its performances are compared with the performances of the classical ESC algorithm. Key Words: ESC, EKF, steady state oscillation, anaerobic digestion processes

A novel speed optimisation scheme for unmanned sailboats by sliding mode extremum seeking control without steady-state oscillation

2021 ◽  
pp. 1-18
Author(s):  
Zhipeng Shen ◽  
Xuechun Fan ◽  
Haomiao Yu ◽  
Chen Guo ◽  
Saisai Wang
Keyword(s):  
Steady State ◽  
Sliding Mode ◽  
Small Deviation ◽  
Extremum Seeking ◽  
Piecewise Constant Function ◽  
Maximum Speed ◽  
Extremum Seeking Control ◽  
Switching Law ◽  
Steady State Oscillation ◽  
Search Control

Abstract This paper proposes a novel speed optimisation scheme for unmanned sailboats by sliding mode extremum seeking control (SMESC) without steady-state oscillation. In the sailing speed optimisation scheme, an initial sail angle of attack is first computed by a piecewise constant function in the feed forward block, which ensures a small deviation between sailing speed and the maximum speed. Second, the sailing speed approaches to maximum gradually by extremum search control (ESC) in the feedback block. In SMESC without steady-state oscillation, a switching law is designed to carry out the control transformation, so that the speed optimisation system carries out SMESC in the first convergence phase and ESC without steady-state oscillation in the second stability phase. This scheme combines the advantages of both control algorithms to maintain a faster convergence rate and to eliminate steady-state oscillation. Furthermore, the strict stability of the speed optimisation system is proved in this paper. Finally, we test a 12-m mathematical model of an unmanned sailboat in the simulation to demonstrate the effectiveness and robustness of this speed optimisation scheme.

Extremum-seeking control for nonlinear systems with periodic steady-state outputs

Automatica ◽  
2013 ◽  
Vol 49 (6) ◽  
pp. 1883-1891 ◽  
Author(s):  
Mark Haring ◽  
Nathan van de Wouw ◽  
Dragan Nešić
Keyword(s):  
Steady State ◽  
Nonlinear Systems ◽  
Extremum Seeking ◽  
Extremum Seeking Control ◽  
Periodic Steady State

Discrimination of Steady State and Transient State of Extremum Seeking Control via Sinusoidal Detection

2013 ◽  
Author(s):  
Baojie Mu ◽  
Yaoyu Li ◽  
John E. Seem
Keyword(s):  
Steady State ◽  
Control Process ◽  
Transient State ◽  
Design Guidelines ◽  
Extremum Seeking ◽  
Detection Scheme ◽  
Extremum Seeking Control ◽  
Detection Techniques ◽  
Steady State Operation ◽  
Selection Of

A major class of extremum seeking control is based on the use of periodic dither perturbation of plant input for extracting the gradient information. Presence of the dither input into the steady state operation is undesirable in practice due to the possible excessive wear of actuators. It is thus beneficial to stop the dithering action after the extremum seeking process reaches its steady state. In this paper, we propose a method for automatically discriminate between the steady state and the transient state modes of extremum seeking control process using the sinusoidal detection techniques. Some design guidelines are proposed for the parameter selection of the relevant sinusoidal detection scheme. The proposed scheme is validated with simulation study.

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